Hello everyone! I bought a GY-87 module sesnor, this module has BMP180, MPU6050 and QMC5883L sesnors. Link amazon: https://www.amazon.es/gp/product/B07HMLRD8Q/ref=ox_sc_saved_title_1?smid=A3U3NV7MT8POQS&psc=1.
I am using Arduino NANO for this project. The connection NANO - GY is:
NANO GY-87
GND GND
A5 SCL
A4 SDA
3.3V 3.3V
Fisrt I used the BMP180 sensor, and it works correct. The serial monitor prints "BMP180 init success".
But when I tried to calibrate the MPU6050, the monitor serial prints "Connection failed in MPU6050".
I upload an example to MPU, that only use the Wire library.
#include <Wire.h>
const int MPU_ADDR = 0x68;
int16_t accelerometer_x, accelerometer_y, accelerometer_z;
int16_t gyro_x, gyro_y, gyro_z;
int16_t temperature;
char tmp_str [7];
char* convert_int16_to_str(int16_t i) {
sprintf(tmp_str, "%6d", i);
return tmp_str;
}
void setup() {
Serial.begin (9600);
Wire.begin ();
Wire.beginTransmission(MPU_ADDR);
Wire.write(0x68);
Wire.write(0);
Wire.endTransmission(true);
}
void loop() {
Wire.beginTransmission(MPU_ADDR);
Wire.write(0x3B);
Wire.endTransmission(false);
Wire.requestFrom(MPU_ADDR, 7*2, true);
accelerometer_x = Wire.read()<<8 | Wire.read();
accelerometer_y = Wire.read()<<8 | Wire.read();
accelerometer_z = Wire.read()<<8 | Wire.read();
temperature = Wire.read()<<8 | Wire.read();
gyro_x = Wire.read()<<8 | Wire.read();
gyro_y = Wire.read()<<8 | Wire.read();
gyro_z = Wire.read()<<8 | Wire.read();
Serial.print("aX = "); Serial.print(convert_int16_to_str(accelerometer_x));
Serial.print(" | aY = "); Serial.print(convert_int16_to_str(accelerometer_y));
Serial.print(" | aZ = "); Serial.print(convert_int16_to_str(accelerometer_z));
Serial.print(" | tmp = "); Serial.print(temperature/340.00+36.53);
Serial.print(" | gX = "); Serial.print(convert_int16_to_str(gyro_x));
Serial.print(" | gY = "); Serial.print(convert_int16_to_str(gyro_y));
Serial.print(" | gZ = "); Serial.print(convert_int16_to_str(gyro_z));
Serial.println();
delay (700);
}
I use I2C_scanner to find 0x68 ADDRESS. Arduino Playground - I2cScanner.
The serial monitor prints:
aX: -6840 | aY: -2064| aZ: 840| tmp: 44.32| gX: -630| gY: 574| gZ: -158
Then I tried to calibrate the sensor, but it doesn't works. I use this libraries: arduino_MPU6050_lib_pack.rar - Google Drive.
The code:
// I2Cdev and MPU6050 must be installed as libraries
#include "I2Cdev.h"
#include "MPU6050.h"
#include "Wire.h"
//Change this 3 variables if you want to fine tune the skecth to your needs.
int buffersize=1000; //Amount of readings used to average, make it higher to get more precision but sketch will be slower (default:1000)
int acel_deadzone=8; //Acelerometer error allowed, make it lower to get more precision, but sketch may not converge (default:8)
int giro_deadzone=1; //Giro error allowed, make it lower to get more precision, but sketch may not converge (default:1)
// default I2C address is 0x68
// specific I2C addresses may be passed as a parameter here
// AD0 low = 0x68 (default for InvenSense evaluation board)
// AD0 high = 0x69
//MPU6050 accelgyro;
MPU6050 accelgyro(0x68); // <-- use for AD0 high
int16_t ax, ay, az,gx, gy, gz;
int mean_ax,mean_ay,mean_az,mean_gx,mean_gy,mean_gz,state=0;
int ax_offset,ay_offset,az_offset,gx_offset,gy_offset,gz_offset;
void setup() {
// join I2C bus (I2Cdev library doesn't do this automatically)
Wire.begin();
// COMMENT NEXT LINE IF YOU ARE USING ARDUINO DUE
TWBR = 24; // 400kHz I2C clock (200kHz if CPU is 8MHz). Leonardo measured 250kHz.
// initialize serial communication
Serial.begin(115200);
// initialize device
accelgyro.initialize();
// wait for ready
while (Serial.available() && Serial.read()); // empty buffer
while (!Serial.available()){
Serial.println(F("Send any character to start sketch.\n"));
delay(1500);
}
while (Serial.available() && Serial.read()); // empty buffer again
// start message
Serial.println("\nMPU6050 Calibration Sketch");
delay(2000);
Serial.println("\nYour MPU6050 should be placed in horizontal position, with package letters facing up. \nDon't touch it until you see a finish message.\n");
delay(3000);
// verify connection
Serial.println(accelgyro.testConnection() ? "MPU6050 connection successful" : "MPU6050 connection failed");
delay(1000);
// reset offsets
accelgyro.setXAccelOffset(0);
accelgyro.setYAccelOffset(0);
accelgyro.setZAccelOffset(0);
accelgyro.setXGyroOffset(0);
accelgyro.setYGyroOffset(0);
accelgyro.setZGyroOffset(0);
}
void loop() {
if (state==0){
Serial.println("\nReading sensors for first time...");
meansensors();
state++;
delay(1000);
}
if (state==1) {
Serial.println("\nCalculating offsets...");
calibration();
state++;
delay(1000);
}
if (state==2) {
meansensors();
Serial.println("\nFINISHED!");
Serial.print("\nSensor readings with offsets:\t");
Serial.print(mean_ax);
Serial.print("\t");
Serial.print(mean_ay);
Serial.print("\t");
Serial.print(mean_az);
Serial.print("\t");
Serial.print(mean_gx);
Serial.print("\t");
Serial.print(mean_gy);
Serial.print("\t");
Serial.println(mean_gz);
Serial.print("Your offsets:\t");
Serial.print(ax_offset);
Serial.print("\t");
Serial.print(ay_offset);
Serial.print("\t");
Serial.print(az_offset);
Serial.print("\t");
Serial.print(gx_offset);
Serial.print("\t");
Serial.print(gy_offset);
Serial.print("\t");
Serial.println(gz_offset);
Serial.println("\nData is printed as: acelX acelY acelZ giroX giroY giroZ");
Serial.println("Check that your sensor readings are close to 0 0 16384 0 0 0");
Serial.println("If calibration was succesful write down your offsets so you can set them in your projects using something similar to mpu.setXAccelOffset(youroffset)");
while (1);
}
}
void meansensors(){
long i=0,buff_ax=0,buff_ay=0,buff_az=0,buff_gx=0,buff_gy=0,buff_gz=0;
while (i<(buffersize+101)){
// read raw accel/gyro measurements from device
accelgyro.getMotion6(&ax, &ay, &az, &gx, &gy, &gz);
if (i>100 && i<=(buffersize+100)){ //First 100 measures are discarded
buff_ax=buff_ax+ax;
buff_ay=buff_ay+ay;
buff_az=buff_az+az;
buff_gx=buff_gx+gx;
buff_gy=buff_gy+gy;
buff_gz=buff_gz+gz;
}
if (i==(buffersize+100)){
mean_ax=buff_ax/buffersize;
mean_ay=buff_ay/buffersize;
mean_az=buff_az/buffersize;
mean_gx=buff_gx/buffersize;
mean_gy=buff_gy/buffersize;
mean_gz=buff_gz/buffersize;
}
i++;
delay(2); //Needed so we don't get repeated measures
}
}
void calibration(){
ax_offset=-mean_ax/8;
ay_offset=-mean_ay/8;
az_offset=(16384-mean_az)/8;
gx_offset=-mean_gx/4;
gy_offset=-mean_gy/4;
gz_offset=-mean_gz/4;
while (1){
int ready=0;
accelgyro.setXAccelOffset(ax_offset);
accelgyro.setYAccelOffset(ay_offset);
accelgyro.setZAccelOffset(az_offset);
accelgyro.setXGyroOffset(gx_offset);
accelgyro.setYGyroOffset(gy_offset);
accelgyro.setZGyroOffset(gz_offset);
meansensors();
Serial.println("...");
if (abs(mean_ax)<=acel_deadzone) ready++;
else ax_offset=ax_offset-mean_ax/acel_deadzone;
if (abs(mean_ay)<=acel_deadzone) ready++;
else ay_offset=ay_offset-mean_ay/acel_deadzone;
if (abs(16384-mean_az)<=acel_deadzone) ready++;
else az_offset=az_offset+(16384-mean_az)/acel_deadzone;
if (abs(mean_gx)<=giro_deadzone) ready++;
else gx_offset=gx_offset-mean_gx/(giro_deadzone+1);
if (abs(mean_gy)<=giro_deadzone) ready++;
else gy_offset=gy_offset-mean_gy/(giro_deadzone+1);
if (abs(mean_gz)<=giro_deadzone) ready++;
else gz_offset=gz_offset-mean_gz/(giro_deadzone+1);
if (ready==6) break;
}
}
Here, firstly prints MPU6050 connection failed, and the final message with the Offsets doesn't appear.
The GY is in horizontal position and facing up. I have been waitig for 4 minutes and nothing appears...
If someone can help me, please!

